1. Field of the Invention
This invention relates to the configuration of the outer surface of golf balls, and particularly to such designs which relate to the pattern of the dimpled surface area of the ball so that when the ball is hit by a putter it will assume a more accurate, predetermined, directional roll.
2. Description of the Prior Art
A pioneer patent in the art of golf balls is the Taylor U.S. Pat. No. 878,254 of Feb. 4, 1908 which taught for the first time that the outer surface of a golf ball should be provided with a plurality of spaced dimples which substantially cover the outer surface. The advantage of this dimpled surface is that it gives stability in flight and also increased lift to the ball. In the words of the Taylor patent, "Its principal object is to obtain better results in the flight of the ball in the direction of a sustained hanging flight giving a flat trajectory with a slight rising tendency particularly toward the end of the flight, than have been possible with balls of known types." A smooth surfaced ball that is driven by a given force at a given angle would stay in the air only 2 seconds, while the Taylor dimpled ball would stay in the air 5 seconds for a good wood shot. This is due to the turbulent air action caused by the dimples on the forward moving ball which is back-spinning. The Taylor dimples take advantage of the Bernoulli Effect, which is well known in the science of aerodynamics. To create a vacuum over the top surface of the ball which causes the ball to rise and have a longer "hang" time in flight. The teachings in this Taylor patent are believed to be found in every golf ball on the market at the present time.
The Hagen U.S. Pat. No. 1,666,699 relates to a golf ball surface configuration comprising annular recesses completely covering the ball. These recesses have concavely curved outer walls and convexly curved inner walls with the result that the outer surface is more nearly smooth all over. Hagen asserts that his golf ball is more accurate in flight and also in putting or rolling along the surface of the ground.
The Beldam U.S. Pat. No. 1,681,167 describes the surface configuration of a golf ball where the primary object is to provide a form or character of surface by which a better "grip" of the club with the ball is obtained without slip or relative movement. Also the surface configuration furnishes a better "grip" of the "green", and hence a truer run. The outer surface is filled with rectangular recesses that are surrounded by cross ribs.
The Fotheringham U.S. Pat. No. 1,716,435 is very similar to the Hagen U.S. Pat. No. 1,666,699 in that it describes a golf ball that is covered with a plurality of annular recesses having concavely curved outer walls. This renders a golf ball that is more nearly smooth all over.
The Nepela et al U.S. Pat. No. 3,819,190 describes a golf ball having dimples in a wide band extending completely around the ball, and the diametrically opposed undimpled portions outside this band having fewer or no dimples allegedly "to decrease the drag on the ball while leaving the lift characteristics substantially the same thereby to cause the ball, for a given striking force, to exhibit directional control." The force tending to slow a conventional golf ball as it travels through the air is commonly referred to as drag. The drag is proportional to the planar area of the ball pushing through the air. With the air film spinning with the ball, the effective planar area of the ball is increased thereby increasing the drag forces imparted on the ball. The patent states that, "any detrimental forces acting to slow the ball in flight will reduce the distance the ball travels." This Nepela patent teaches concentrating the dimples in a circumferential band centered about a circumferential line or great circle around the ball. Then the ball is teed with the plane of the band aimed along the desired direction of flight. This patent states, "By making the surface regions outside the band smoother, i.e., fewer dimples, less air turbulence results and a thinner film of air is carried by these areas thereby reducing the drag on the ball." This patent also states, "For putting, the undimpled areas between dimples form an even spherical surface for control of the ball." The patent states that the large undimpled areas exhibit a spinning "barbell effect", thereby doing away with the sidewise spin which would cause curving of the flight path.
The Shaw et al U.S. Pat. No. 4,142,727 has a golf ball with a surface pattern of dimples arranged to provide at least 12 and as many as 30 symmetrically disposed bald patches. The purpose of these bald patches is to increase the distance of the ball, but the statistics given in this patent appear to show a minuscule improvement of 2 yards in 230 yards. This patent does not discuss any change or improvement in the putting of the ball. Also each bald patch is narrow and elongated in shape; i.e. a width of 0.856 dimple diameters and an area of 4.01 times the mean dimple area. These bald patches are too small for serving as putting targets.
Also, it is known in the prior art to imprint the brand name of the manufacturer on the cover of the ball, and to assist this procedure an undimpled patch may be reserved of such a size to provide a smooth surface for printing only.